Allegations that hackers hijacked the Fox NewsTwitter feed Monday and used it to tweet incorrectly that President Obama had been assassinated have showed the dark side of social media.

The incident is a cautionary tale about how online mischief-makers are using social media as an important tool to spread misinformation or even gain access to personal computers.

In some cases, the attack is a direct intrusion, as might have been the case with Fox Monday, with pranksters taking control of social-media accounts. But hackers are also bending social media to more subtle purposes, snaring unsuspecting users with messages that appear to be funny chats or videos.

Both the Secret Service and Fox have opened investigations into the Monday incident. Jeff Misenti, vice president and general manager of Fox News Digital, said in a statement: "The network was not in control of the account once it was hacked, and Twitter was unreachable until late morning eastern time yesterday. The tweets were taken down as soon as Twitter gave back control of the account to the network.”

The Hacker News, a website, reports that a new group called the Script Kiddies is behind the digital takeover. “I have faith that the members of the Script Kiddies will remain hidden,” an alleged group member told The Hacker News. While the source didn't divulge any plans for future attacks, “we have brainstormed several ideas.”

In some cases, this can be easier than in others. Social media's greatest virtue – its variety of voices – is also its greatest weakness as a news source, given that many of those voices have no professional standards for reporting.

Too much social media – “including Twitter – bypasses traditional editorial judgment,” says Professor Goedkoop via e-mail. And “some members of the public are prone to egregious mischief,” he adds.

Yet Monday's mistaken tweet also shows that even mainstream media accounts are not always trustworthy. As news companies adopt social media strategies, incidents of deliberate, organized hacking raise serious concerns about the lack of security protocols, says Michael Davis, head of Savid Technologies.

The broader problem highlighted by the Fox News tweet is that the social media universe has its fair shares of hucksters and malcontents, some of whom seek to bend Americans' trust in technology toward malicious purposes.

Hackers have used Twitter, Facebook, MySpace, "and other social-media sites to convince users to provide usernames, passwords, or even to simply to spread lies in order to damage an online reputation,” says Mr. Davis via e-mail.

Last month, for example, McDonalds had to vigorously fight a fraudulent tweet that went viral. The tweet appeared to show a sign on the door of a McDonalds saying that the restaurant was charging African-American customers more “as an insurance measure due in part to a recent string of robberies."

Companies and social-media sites must focus more attention on security, says Davis. But consumers have to get more savvy as well.

Whether it’s a message on Facebook from a friend “that tells them to look at a new funny video (which really is a hacker that wants to steal their identity) or a tweet that contains a malicious link to a site that breaks into your computer, users have to analyze the intent of the message and determine if there is malicious activity occurring," he adds.

While social media thrives on many its many voices, it also is built on the trust that users aren't deceiving or taking advantage of one another. News outlets in particular cannot afford to lose credibility by treating social media without care, says Rich Hanley, director of the graduate journalism program at Quinnipiac University in Hamden, Conn.

“They need to pressure Twitter to adopt tighter security arrangements with a faster response time to block accounts that have been compromised by hackers," he says. "The importance of social media has evolved to the point where a professional staff needs to be monitoring and posting information, instead of delegating the work to interns or less-than-seasoned personnel.”

Adds Len Shyles, a professor of communication at Villanova University in Pennsylvania. “Trust in our system of communication is vital,” he says. “It is in everyone’s interest to be able to have faith in this global marketplace of ideas.”